The present invention is directed generally to an improvement for the transmission of an agricultural planter implement which enables the selected planting population rate to be further reduced at times from the tractor operator's station to accommodate driving from irrigated to non-irrigated land, for example.
Most agricultural planter implements are equipped with adjustable transmissions for selecting a desired planting population rate. This rate is set by training a chain around a selected pair of various sized sprockets on a pair of the transmission shafts. Since readjustment of the transmission sprockets requires the implement to be disabled for approximately two to ten minutes, this is not a practical means for repeatedly adjusting the population rate at short intervals.
A variable speed belt drive system has been proposed which can be operated from the tractor cab while continuously planting but the belts are not easily controlled and adjustments require considerable time. The variable pulleys for the belts are electrically controlled and monitored. The implement may traverse a couple of hundred yards by the time the pulleys are adjusted, monitored and corrected for any over or under adjustment.
Other planter implements have hydraulic population adjustment devices but these require an extra hydraulic outlet on the tractor and are practically prohibitively expensive.
These and other problems of the prior art are believed to be resolved by the present invention.
Accordingly, a primary object of the present invention is to provide an improved planter population reduction drive unit.
Another object is to provide a population reduction drive unit which is capable of precise and practically immediate population rate adjustments.
Another object is to provide a population reduction drive unit which may be quickly and easily operated from the tractor cab to adjust the population rate while continuously planting.
Another object is to provide a population reduction drive unit which is adapted for installation on existing planter implements.
Finally, an object is to provide a population reduction drive unit which is rugged in construction, economical to manufacture and efficient and dependable in operation.